Refrigeration system



3 May 1927 G. HILGER REFRIGERATION SYSTEM Filed Oct. 12, 1925 Patented May 3, 1927.

UNITED STATES GEORGE HILGER, OF CHICAGO, ILLINOIS.

REFBIGERATIOR SYSTEM.

Application filed October 12, 1935. Serial m). 81,878.

The invention relates to a. refrigeration system adapted for use in show cases, refrigerators, cold storage chambers and like coolers.

More particularly the invention relates to refrigeration systems in which air to be circulated through a storage chamber is cooled by mixing it with a liquid cooling medium in the form of a spray or finely divided particles. It has been found in practice that aircooled in this Way contains appreciable quantities of the cooling medium suspended therein as a fine fog. Some of this fog is carried forward by the circulating air and precipitates or settles out in the storage chamber. Such a system cannot be utilized practically for refrigerating food products for the reason that most foods decay rapidly when wet and will become tainted or discolored if exposed to brine. Furthermore, the use of spraying systems in show cases or display counters has proven impracticable due to the fact that moisture is deposited upon the glass walls thereby defeating the very purpose of the display feature of the refrigerator.

The primary object of the present invention is to provide a new and improved refrigeration system of the above type having an efficient means for removing excess moisture in the air current before it passes into the storage chamber, thus preventing precipitation or settling .out of the cooling mediumwithin the storage chamber'and permitting higher pressure to be used at the spray nozzles.

I attain ing a novel means for dehydrating t e cooled saturated air before it enters the storage chamber.

A general object of the invention is to rovide a novel spray refrigeration system w ich is economical, e cient and reliable in o ration and which is particularly adapte for use in, the refrigeration of food products.

Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

Fig. 1 is a fragmentary view in vertical section of a refrigerator embodying the features of my invention. 7 a

Figs. 2 and 3 are sectional views taken alongthe lines 2-2 and 3-3 respectively of ale 1 have fil W 1 in il? d ir g i this object, generally, b provid- 11 will describe in detail the preferred embodiment of the invention, it is to be understood that I do not intend to be limited thereby to the particular form disclosed nor to the part cular application set forth, but aim to cover all modifications and alternate constructions falling within the spirit and scope of the invention as expressed in the appended claims.

The refrigerator chosen for the purpose of illustrating the present invention 'is of the type commonly used in stores for displaying meats and other perishable foods. It comprises generally a box-like casing providing an upper compartment. 10 for storing food products anda lower compartment 11 'in which air is cooled and then circulated through the storage compartment 10. Herein I have shown a casing of substantial length equipped with duplicate refrigerating units, one for each end of the casing; but it will be understood that one unit only may be employed especially in casings of short length. r

The compartment 10 of the refrigerator casing is defined by insulating end walls 12 and front, top, and rear walls 13, 14 and 15 respectively which are made of glass so that the food products in the compartment 10 may be observed. In the present instance the rearwall 15 is inclined and made in the form of sliding doors which may be opened and closed at will. Walls 16, 17 and 18, made of suitable insulating material, define the front, bottom, and rear walls respectively of the lower or refrigerating compartment IIorizontal partition walls 19 of suitable material separate the upper and'lower compartments at opposite ends of the casing,

except for passageways 20 at the ends and'a passageway 21 located near the center of the casing. With this arrangement, it will be observed, air from the upper compartment 10" may be circulated througheither portion of the lower compartment 11 and back into the compartment 10 in a continuous cycle. The

partition walls 19 constitute supports for the products placed in the compartment 10.

Mounted within the compartment 11 and covering substantially the entire bottom wall thereof are two relatively shallow tanks 22 containing water, brine or other suitable cooling medium. Preferably, though not necessarily, the liquid in the tanks is cooled by artificial refrigeratign, Thus, in the pres:

ent instance, a refrigerating cpil 23, positioned within the tank shown in Fig. 1, 1s

supplied with a suitable refrigerant through an inlet pipe 23. Before passing through tank in the other end of the casing.

' vapor, the air, of course,

To effect an eflicient heat interchange be.- tween the air in the refrigerating compartment 11 and the liquid cooling medium, the latter is spra ed or atomized into the compartment 11 f i'om suitable nozzles 25 preferably positioned beneath the central passageway 21. For this purpose, a suitable power pump 26 mounted beneath the refrigerator draws cooling liquid from the tanks throu h pipes 27 and delivers it under pressure to t e nozzles. Preferably, the nozzles are directed horizontally toward opposite ends of the refrigerator so as to induce a slow continuous circulation of air from the compartment 10 through the passageway 21 and the refrigerating compartment 11 back into the storage com artment throug'hthe passageways 20. T c direction of flow of the air, in the present arrangement, is indicated by arrows in Fig. 1. Thus, the air entering the spray chamber comes in direct contact with an infinitely large cooling surface; consequently its temperature is uickly and efi clently reduced. A third unction of the cooling sprav is to wash out the foul gases which are often given 01f by food products. The gases thus removed can be removed from the system by simply using fresh cooling liquid which can be done cheaply, espepially where water is employed for spraymg.

ing liquid sprayed into the refrigerating chamber falls back into the tanks to be used over again. -A considerable part, however, may be carried'forward with the cooled air as a fine suspended f0 and as water being saturated by the spray. It is an important feature of the present invention to remove the moisture in t e cooled air or at least such a portion of it as might precipitate or settle out if carried into the storage chamber 10.

As a primary means for dehydrating the cold air after it has passed through the spray, a plurality of baflle plates or trays 28 are arranged withinthe compartment 11 to provide inclined passagewa in the path of the air. If desired, the ba plates may be fastened to the front and rear walls of the compartment. These battles provide Of course, the major portion of the coollarge cold surfaces u on which the suspended drops of water 00 lect and unite to form largeudrops that flow back into the tank. Changlngthe direction of flow of the air as it passes through the bafile passages also assists in coagulating the suspended tog par ticles.

Any of the fog which escapes precipitation in the baflles is carried forward with the air into a cooling zone surrounding the coil 24 previously alluded to. This coil, being cooled directly by a refrigerant and therefore maintained at a tem erature below that of the air cooled by tie spray, will cool the air below its dew point temperature. This will increase the refrigeration capacity of the air although its further purpose is to effect a further dehydration of the air by condensation of the water vapor to form minute water particles which unite with each other and with the suspended fog particles or mist to form lar er and heavier particles which fall out of the moving air, dropping into the tank or depositing upon the coil as, before it enters the storage compartment. Thus, it will be observed, that by the time cold air reaches the storage compartment 10, any excess moisture which might have a tendency to precipitate or become deposited upon the food products, will have been removed. Also, it will be seen that the larger drops of moisture, having been separated out in the primary precipitation efiected by the baflle plates or trays 28, are prevented from coming in contact with and freezing upon the coil extension 24:.

In the storage compartment 10 the temperature of the air rises due to the absorption of heat from the food products, and the degree of saturation of the air with water vapor is correspondingly decreased. Thus, if it should happen that any suspended par ticles should escape precipitation in the cooling zone around the coil24,- they will, when they enter the compartment 10, tend to pass into the air as Water vapor. It is an advantage, therefore, to condense out as much water vapor as possible in the refrigerating compartment so that there will be a greater tendency for evaporation of any mechanically suspended particles which might be carried into the storage compartment.

Thus I have provided an effective means foreliminating the settling out or precipitation of wateror brine upon the food prod acts in a refrigerator cooled by the spray system. The parts are compactly arranged and can be conveniently placed in the space provided by an ordinary display counter.

, Another advantage of the present system is that it may be operated intermittently without materially c anging the temperature within the storage compartment. Thus, by pumping excess quantitles of refrigerant through the coil 23, slush ice may be frozen llltl l ll 1 taining the cooli in the tank without interfering with the normal operation of the spray. Then, when the system is shut down as is often the case during the night, the storage compartment will be maintained cold by natural circulation of the air cooled by the ice then stored in the tank 22. This important advantage is attained by placing the tank conli uid within the cooling compartment in c ose proximit to the storage compartment with which t e cooling compartment communicates. A further advantage of this compact arran ement is that loss of refrigeratlon by ra iation is minimized.

With the present system it is possible to use higher spray pressures and to spray larger volumes of cooled l' uid thereby circulating the air through t e system more rapidly than would be possible if the cooling coil 24 were not rovided.

' By reason of the act that the pan contaimng'the cooling liquid is located in the spray; compartment the sprays serve as an agitating means for the water in the pan so as to increase the effective heat transfer between the water and the air passing thereover on the one hand and between the water and cooling coils on the other. Thus the sprayed liquid strikin the surface of the liquid with considerab e force roduces not only a surface "agitation thereo but induces a movement of the upper surface of the liquid so as to set up a circulation of the liqpid in the pan and about the coil 23 su merged therein.

A further advantage in having the container for-the cooling liquid located in the bottom of the sprayin com artment is that less power is require in t e-operation of the sprays as compared to the nor arrangements in which the cooling liquid is permitted to fall a substantial distance to a tank located below, fromyvhich it has to be pumped up against the action of gravity, pi e friction, etc.

gt should also be noted that the cross sectional area of the s raying space is large and unrestricted, whi e the air circulation openings 20 and 21 are relatively small. By this arrangement the velocity of the air through the s raying space is relatively slow so that the liquid particles constitutin the spray are given time to drop out o the air current. This minimizes the tendency of mist to be carried over into the display or storage chamber, and together with the dehydrating coils insures that the air passing into the display chamber shall not be so laden with moisture as to deposit moisture .upon the food products or upon the walls of the case.

I claimasmy invention: I

' 1. refrigeration. system 'having,- in combination, "an elongated horizontally disposed cooling compartment having an inlet and an outlet at opposite ends, a storage compartment communicating with said inlet and outlet and adapted to contain products to be refrigerated, a source of cooling liquid, spray means located in said cooling compartment and disposed so as to direct a spray of the cooling liquid longitudinally of the cooling compartment thereby inducing circulation of the cooled air into said storage compartment, and means maintained at a temperature below that of the spraycooled air and maintaining a cooling zone at a point spaced a substantial distance fromsald spray means, the last mentioned means normally acting to further cool the air and to effect a separation of mist therefrom before it comes in contact with said prod ucts.

' 2. A refrigeration system having,'in combination, an elongated horizontally disposed cooling compartment having an inlet and an outlet at opposite ends, a storage compartment in communication with said inlet and outlet, a source of cooling liquid, a spray nozzle located in said cooling compartment near said inlet and disposed 'so as to direct a spray of the cooling liquid longitudinally of the cooling compartment thereby inducin circulation of the cooled air toward sai outlet into'said storage compartment, means to deliver said cooling liquid to said nozzle under pressure, a cooling coil positioned in said cooling compartment a substantial distance from said nozzle and in\the path of the air cooled by the liquid from said nozzle, and means for maintalning said coil at a tern erature lower than the air cooled by sai spray liquid whereby to effect. a separation of moisture particles from the air before it passes into the storage compartment.

' 3. A refrigeration system having, in combination, an elongated horizontally disposed cooling compartment having an inlet and an outlet at opposite ends, a storage com-- partment in communication with said inlet and outlet, a source of cooling liquid, a.

spray nozzle located in said cooling compartment near said inlet and disposed so as to direct a s ray of the cooling liquid longitudinally o the cooling compartment thereby inducing circulation of the cooled air toward said outlet into said storage compartment, means to deliver coolin liquid to said nozzle under pressure, a coo ing coil positioned in said cooling compartment in the path of the air cooled by the liquid from said nozzle, means for maintaining the coil at a temperature lower than the air cooled by said spray liquid, and baflle means positioned between said nozzle and said coil.

4. A refrigeration system having, in combination, a casing, a partition wall dividing said easing into an elongated cooling com- 1 said nozzle under pressure, the surface of the liquid in the tank defining the bottom of the spraying space. v

5. A refrigeration system having, in combination, a casing, a partition wall dividing said casing into an elongated cooling compartment and a storage compartment communicating with said cooling compartment at its opposite ends, an open tank positioned in said cooling compartment to contain a cooling liquid, means immersed in the liquid in said tank for cooling the same, a s ray nozzle positioned near the inlet end 0 the cooling compartment and directed longitudinally of said compartment so as to cool the air in the cooling compartment and to induce circulation of the cooled air into said storage compartment, and means to deliver liquid from said tank to said nozzleunder pressure, the surface of the liquid in the tank defining the bottom of the spraying space.

6. In a refrigeration system, a casing providing two interconnected compartments, a container for a cooling medium, a refrigerating coil having a portion positioned in said container and a portion projecting into one of said compartments, and means formixing said cooling medium with said air to cool it, said mixing means serving to'induce circulation of said cooled air over the projecting portion of said coil into said other compartment. 7

7. In a refrigeration system, a casing providing two interconnected compartments adapted for the free circulation of air through them, a tank in one of said compartments for containing a cooling liquid,

means for mixing said cooling li uid intimately with the air above said ta to cool said air, and cooling means for said liquid including a refrigerating coil having a portion positioned in said tank and a portion rising above the liquid in said tank into the path of the cooled air flowing to said other compartment.

8. In a refrigeration system, the combination of a casing providing a cooling compartment, a tank disposed in said compartment and adapted to contain a coolin liquid, a refrigerating coil to cool the liqui in said tank, said coil having a portion rising above one end of the tank, a spray nozzle located at the other end of said tank and arranged to direct a spray of liquid lon itudinally of the tank, and means to supply the liquid to said nozzle under pressure.

9. A spray refrigeration system for coolers having intercommunicating spraying and storage spaces, comprisin in-colnbination, an open container for coo ing liquid located in the bottom of the spraying space, spray means adapted to discharge a cooling liquid directly over said container, thus agitating the surface of the liquid while inducing a fiowof air through the spraying space into the storage space, means in the container for cooling the liquid therein, and means including a pump adapted to draw liquid from said container and supply it under pressure to said spray means.

10. A spray refrigeration system for coolers having intercommunicating spra ing and storage spaces, comprising, in com ination, a container for cooling liquid located in the bottom of the spraying s ace, spray means adapted to discharge a coo ing liquid directly over the surface of the liquid 1n said container so as to induce a flow of air through the spraying space into the storage space, a coil immersed in the liquid in the container and adapted to be su plied with a refrigerant so as to cool t e liquid in the container, and means including a pump adapted to draw liquid from said container and supply it under pressure to said spray means.

In testimony whereof, I have hereunto afiixed my signature.

GEORGE HILGER. 

